Environmental mycobacteria in northern Malawi: implications for the epidemiology of tuberculosis and leprosy | Epidemiology & Infection | Cambridge Core (original) (raw)

Hostname: page-component-89b8bd64d-46n74 Total loading time: 0 Render date: 2026-05-14T00:08:47.830Z Has data issue: false hasContentIssue false

Published online by Cambridge University Press: 16 July 2001

P. E. M. FINE

Affiliation:

Department of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, Keppel Street, London WC1E 7HT

S. FLOYD

Affiliation:

Department of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, Keppel Street, London WC1E 7HT

J. L. STANFORD

Affiliation:

Department of Medical Microbiology, Royal Free and University College Medical School, Windeyer Institute of Medical Sciences, 46 Cleveland Street, London W1P 6DB

A. KASUNGA

Affiliation:

Karonga Prevention Study, PO Box 46, Chilumba, Karonga District, Malawi

S. CHAGULUKA

Affiliation:

Karonga Prevention Study, PO Box 46, Chilumba, Karonga District, Malawi

D. K. WARNDORFF

Affiliation:

Department of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, Keppel Street, London WC1E 7HT Karonga Prevention Study, PO Box 46, Chilumba, Karonga District, Malawi

P. A. JENKINS

Affiliation:

Bryn Glas, Llangcitho, nr Tregaron, Cardiganshire SY25 6TR, UK

M. YATES

Affiliation:

Mycobacterial Reference Laboratory, Kings College Hospital (Dulwich), East Dulwich Grove, London SE22 8QF

J. M. PONNIGHAUS

Affiliation:

Karonga Prevention Study, PO Box 46, Chilumba, Karonga District, Malawi Pappelweg 08548 Syrau Germany

Article contents

Abstract

Core share and HTML view are not available for this content. However, as you have access to this content, a full PDF is available via the 'Save PDF' action button.

More than 36000 individuals living in rural Malawi were skin tested with antigens derived from 12 different species of environmental mycobacteria. Most were simultaneously tested with RT23 tuberculin, and all were followed up for both tuberculosis and leprosy incidence. Skin test results indicated widespread sensitivity to the environmental antigens, in particular to Mycobacterium scrofulaceum, M. intracellulare and one strain of M. fortuitum. Individuals with evidence of exposure to ‘fast growers’ (i.e. with induration to antigens from fast growers which exceeded their sensitivity to tuberculin), but not those exposed to ‘slow growers’, were at reduced risk of contracting both tuberculosis and leprosy, compared to individuals whose indurations to the environmental antigen were less than that to tuberculin. This evidence for cross protection from natural exposure to certain environmental mycobacteria may explain geographic distributions of mycobacterial disease and has important implications for the mechanisms and measurement of protection by mycobacterial vaccines.

Information

Type

Research Article

Copyright

© 2001 Cambridge University Press